MIPS_315a Sky Backgrounds


IOC-MIPS_315a       10540C          
Title:     Characterize MIPS Behavior as a Function of Sky Background            
                   
Objective:     Determine whether latent image behavior, responsivity, and photometric stability have any dependence            
      on sky background levels.            
                   
Description:     Point sources of approximately the same brightness will be observed in regions with ~ 1 MJy/sr, 10 MJy/sr, and 100 MJy/sr backgrounds.            
including flow / state diagram     Each point source will be observed using both photometry and scan map AOTs.            
      At each of three locations corresponding to the three sky levels:            
      1) Construct a slow mode scan map including both forward and reverse scans.            
      Integrate for a total of 100 seconds on the source.            
      2) Switch to photometry mode and acquire:            
      A 4x4 dither using 10-second exposures at 24um.          
        A 4x4 dither using 10-second exposures at 70um with coarse pixels.          
        A 4x4 dither using 10-second exposures at 70um with fine pixels.          
        At 6 positions using 10-second exposures at 160um.          
                   
Place in Schedule:              
(relative to water shed events)     After the aperture cover is opened.            
                   
Required Conditions:                
      MIPS apertures must have been located and basic instrument functionality checked.            
      The telescope induced background at each wavelength should be less than 10% of the sky:            
        24um 70um 160um Chart gives W/m^2/sr    
      1MJy/sr 3.00E-09 1.00E-09 5.00E-10      
      10MJy/sr 3.00E-08 1.00E-08 5.00E-09      
      100MJy/sr 3.00E-07 1.00E-07 5.00E-08      
    1MJy/sr 25 10 5.5 on terms of T    
      10MJy/sr 28 12 6      
      100MJy/sr 30 13 7      
                   
                   
Resources:                  
  duration (best estimate)         3 hrs.      
  real time downlink (Y / N)         no      
  special post event actions (Y / N)         no      
  The scan map will generate 3x2x3x20 DCEs=360DCEs.                
  The photometry mode will generate 3x(16+16+16+6) DCEs = 162 DCEs                
                   
Outcome:                  
  description       We will understand whether any modifications to MIPS operation as      
            a function of sky background are needed.      
  can proceed in parallel with other activity       no, requires dedicated pointing      
  must outcome be confirmed before next event / test /activity         no      
  method of confirmation (sensor TLM, data analysis, etc.)         data analysis      
  estimate of data turn around if required for confirmation         N/A      
                   
Unique or included in planned AOT?                  
            Uses planned AOTs (photometry and scan map).      
                 
Contingency Plan:                  
"What if..."           If test fails it should be repeated.      
                   
IOC Critical           Y      
                   
References:                  
                   
Template last updated:           9/6/99      
            M. Rieke      
                   


Last Updated on 10/7/99
By Marcia Rieke
Email: mrieke@as.arizona.edu